Method of conditioning hot wire gas detectors



July 12, 1955 L. F. BONNER 2,713,010

METHOD OF CONDITIONING HOT WIRE GAS DETECTORS Filed Oct. 19, 1955 32PLAT/HUI HIRE 61. ocx SHAFT FIG. I.

INDICATOR 14 IIIDICAT'INGV ELE'EIVT 0/ -40 HETIH'LALCOHOL FROU DRILL/N6OPERATION INVENTOR. FIG. 4.

Louis E Bonner;

a Ew A 7' TOR/V5 K United States Patent 2,713,010 Patented July 12, 1955Fice METHGD 6F CONDITIQNING HOT WIRE GAS DETECTORS Louis F. Bonner,Houston, Tex., assignor, by mesne assi ments, to Esso Research andEngineering Comp .113 Elizabeth, N. 3., a corporation of DelawareApplication @ctober 19, 1953, Serial No. 386,845

3 Claims. (Cl. 134--2) samples are tested to determine the presence ofhydrocarbons from subsurface earth formations. The specific feature ofthe invention is contacting the hot wire with vapors of a volatileoxygenated organic compound such as the aliphatic alcohols, aliphaticketones and aliphatic ethers, these oxygenated compounds having a carbonchain in which there are no more than three carbon atoms. The vapors arethen ignited whereby any deposits on the hot wire are removed bycombustion of the volatile oxygenated organic compounds.

The present invention also is concerned with apparatus for use in mudand sample logging in which oil-emulsion muds are employed comprising ahousing defining a chamher having an electrical element arranged in thechamber. This element becomes fouled with combustible deposits on use insaid mud logging operations where oil-emulsion muds are employed. Theapparatus comprises a container adapted to receive a body of a volatileoxygenated organic compound selected from the group consisting of thealiphatic alcohols, ketones and ethers having a carbon chain of no morethan three carbon atoms. The container is provided with means forinjecting air thereinto at a lower point in the container below thesurface of the body. A conduit is connected to the container at an upperpoint remote from the lower point and above the surface of the body.This conduit projects into the container and is partially orsubstantially enclosed by baffie members in the container which prevententry of the liquid into the conduit. The conduit is connected to anintroducing means for introducing the combustible mixture into thechamber. The chamber is provided with means for energizing theelectrical element to ignite the mixture and burn off combustibledeposits. The air injection means may comprise a plunger and a biasingmeans, such as a spring, for causing the plunger to inject air in thecontainer. Likewise, the air injection means may comprise a solenoidoperated plunger which is electrically energized.

The invention will be further illustrated by reference to the drawing inwhich:

Fig. l is an illustration of a preferred embodiment showing the biasedplunger for injecting air into the container;

Fig. 2 is an illustration of a solenoid operated plunger; Fig. 3 is awiring diagram of the hot wire detector; and Fig. 4 shows theapplication of the apparatus of the present invention to mud logging.

Referring now to the drawing and particularly Fig. 1, numeral 11designates a hot wire detecting device which is provided with electricalleads 12 connected to a recorder or indicator 13 of the balanced-bridgetype. The indicator 13 has a scale 14 and an indicating means 15 to showthe deflection of the instrument. The indicator 13 is provided withelectrical leads 18a and 18b for energizing the hot wire from a batterysuch as 36.

The apparatus includes a container 19 in which is arranged a body of thevolatile oxygenated organic compound Ztl. The container is provided withan inlet pipe 21 which leads to a lower point in the container below thesurface 22 of the body of volatile oxygenated organic compound. The pipe21 is connected by a coupling 23 to a check valve 24 which, in turn, isconnected by conduit 25 to a plunger mechanism generally indicated bythe numeral 26 and including a piston or plunger 27, a plunger shaft 28and a biasing means, such as spring 29, which normally urges the plunger27 downwardly. The lower end of the spring 29 bears against the plunger27 while the upper end is confined by an annular sleeve 3b. The plungermechanism generally indicated by 26 has a cove 31 through which theshaft 28 loosely projects. The shaft 23 is provided with a shoulder 32.Arranged adjacent the shoulder 32 is a cam or eccentric 33 connected bymeans of a shaft 34 to a clock mechanism or suitable other energizingmeans.

Connected to the container 19 is a conduit 35 which projects into thecontainer 19. The projection of the conduit 35 in the container 19 ispartially or substantially enclosed by bafile members 36 and 37 whichserve to prevent entry of liquid in the conduit 35. The conduit 35 isconnected to a check valve 3? for introducing gaseous mixture into theindicating element 11. The indicator element is provided with ports 4-9to allow the gaseous mixture to circulate freely over the hot wire ordetecting element and for withdrawal of the combustion products.

The container 19 is provided with a closure member 41 which isthreadably connected by threads 42 to the container, the conduit 35passing through the closure member 41.

The check valves 24 and 39 are constructed similarly and are comprisedof spheres or balls 43 which are designed to seat against seats Thespheres 43 are biased against the seats 44 by means of a biasing meansor spring 4-5 arranged on a spring member 36, the spring 45 and thespring member 46 being mounted on a plate 47 arranged in the checkvalves 24 and 39.

Referring now to Fig. 2 in which the air injecting means is a solenoidoperated plunger, the numeral 59 designates generally the solenoidoperated mechanismin which is arranged a plunger 51, provided withO-ring seals 51:: and 51b which is normally biased in an upward positionby a spring 52. The plunger 51 is provided with a shaft 53 on which isarranged a shoulder 54. A closure member 55 through which the shaft 53projects is threadably connected by threads 56 to the solenoid member56, the shaft 53 being slidably sealed by an O-ring S7. Wound around theupper end of the member 55? is a solenoid winding 58 which is connectedby electrical connections 5'9 and 6% to a source of power illustrated bya battery 61. Arranged in the circuit is a solenoid switch 62 which iseonnec ed to a snap switch assembly 63 which carries a stroke adjustmentassembly 63a and which has a projecting means 6%, the snap switchassembly and the solenoid switch being connected by a spring 64.

The solenoid assembly 50 is provided with first and second air intakecheck valves 65a and 65b, respectively, having spheres 66a and 66bbiased against the seats 57a and 6711 by means of springs 63:: and 68b.A bleeder control valve 69 is provided to fit against the seat 70 whichis actuated manually by a valve wheel 71, the valve housing 72 beingprovided with a port 73. Thus bleeder valve 69 controls the rate ofreturn of plunger 51 and,

therefore, the time cycle of injection.

' being connected by means of electrical connections 12 to the recorderor detector element 13; The Wheatstone bridge, which is generallyindicated by the numeral 85,

i is provided witha source of power, such as battery 86, and connectedthereto by .means of electrical connections 18a and718b. An ammeter 89is arranged in electrical connection 18a and is provided with amperecontrol means, such as a resistor 90.

The apparatus of'the present invention may suitably be used in mudlogging operations, such as illustrated in Fig. 4,.in which a mud line100 is connected to a drilling operation, not shown, and delivers mud toa mud pit, not

shown. The mud line 100 isprovided with a standpipe 101 which allows themud to rise therein as a column 102 due to the pressure head. Above themud column 102 in standpipe 101' there is a vaporous atmosphere 104 inwhich the indicator element 11 is arranged as shown.

The standpipe 101 is provided witha closure member 103.

Carried through. the closure member 103 are the electrical connectingmeans 12 leading to the recorder 13 -which has been described. Alsocarried through'the closure member 103 is a conduit 38 including thecheck valve 39 which is connected to the conduit 35. The elec- 'tricalconnections 12.may be carried either through the closure member 103 orthrough the wall of the standpipe 101. vBaflie 105 diverts mud from theline, 100 through the standpipe 101 and assures continuous mud supply tothe system.

. The device of the present invention works in the following'manner withrespect to Figs. 1 and 3:

For the purpose of this description, it will be assumed that the hotwire element 80 which may be a fine platinum wire having an overallcoiled length of A to /8 of an inch has become fouled with depositsresulting from well logging operations. The device of Fig. 1 isconnected to the indicating element 11 including a platinum wire 80 andair is injected into the container 19 by operating the shaft 34; as theeccentric or cam 33 rotates in the direction-indicated by the arrow, thecam bears 7 against the'shoulder 32 raising the shaft 28 embracing thespring 29. As the cam or eccentric continues the rotation, the collar 32is released allowing air to be forced downwardly by the plunger 27, theair being sucked or drawn past the plunger 27 as itis raised by therotation of the cam. When the plunger is released from the high part ofthe earn, the plunger is forced downwardly and the air is forced throughthe check valve 24 causing the sphere 43 to bear against the spring 45.The air hobbies in;

check valve 65b by the sphere 66b moving off seat 6712' and the strokeadjustment screw 63a is then contacted and caused ,to rotate.

' the center of the spring 64, the snap switch assembly d ii gized byelectrical connections 18 and 18a by battery 86. 7 As the combustibledeposits are removed from the wire,

the indicating means 1 5 Will become deflected and then returned tozero.

The device of Fig. 2 operates in a similar manner to supply air to thecontainer 19.1 With reference to Fig. 2

sembly 50, air is drawn in below piston 5, through second 63b will snapthe solenoid switch 62 into a closed position thereby actuating thesolenoid again and pulling the plunger shaft 53 downwardly compressingthe spring 52, air having been trapped below the plunger 51 on theupstroke of the plunger 51 causing air to pass through the first checkvalve 65a forcing the sphere 66:: off the seat 67a. The operation withrespect to Fig. 2 thereafter is similar to that of Fig, 1.

In the operation with respect to Fig. 4, the mud flowing through the mudline 100 will rise as a column 102 in standpipe 100 and provide avaporous atmosphere 103. The detector element 11 including the platinumwire 80 is in contact through ports 40 with the vaporous atmosphere. Byenergizing the hot wire,the presence of combustible vapors in theatmosphere 104 may be determined on the scale 14 by the indicating means15.

When the hot Wire 80 becomes fouled with combustible products, volatileoxygenated organic compounds are introduced by introducing means 38 ashas been described and the combustible deposits. removed from the wire80. Thereafter the mud logging operation may be resumed, the removal ofcombustible deposits being conducted periodically and automatically asoccasion re-' quires.

The present invention is particularly adaptable for use emulsion mudsare .used. In fact, heretofore it has been substantially impossible toconduct mud logging operations where oil-emulsion muds have beenused.Efforts have been made to remove deposits from platinum wires using hotwire detectors by. injecting vapors of gasoline and light hydrocarbonsinto the detector element and then energizing the hot wire to burn offthe deposits. This has been unsuccessful in that the longchainhydrocarbons either do not burn with a sufiiciently hot flame or leavein themselves a depositwhich interferes with the accuracy of the device.

'In mud logging where a well is drilled with oil-emulsion mud, the hotwire gas detector rapidly becomes inoperative due to the coating formedon the element. Prior to the present invention, the remedy was to removethe elementor either replace it or clean it by burning out usinghydrocarbon vapors. As will be clear, this requires considerable timeand had to be performed many times a day, such as possibly every 15minutes. The present invention obviates this difficulty since the deviceof the present invention may be connected to the hot wire detector andautomatically and periodically employed to condition the element withoutremoving it from the gas collection chamber. Thus the cam, such asdescribed in Fig. 1, may be run at a controlledspeed by a suitable gearwhich may be variable from one revolution in 5 rninutes to 1 revolutionan hour and likewise with respect to the solenoid actuated embodiment.

While especially useful in operations involving oil emulsion muds, thepresent invention is also applicable to use in logging drill cuttings,examination of bottom hole and side wall cores, aqueous drilling mud,and any media which comes into contact with. subsurface formationswhichmay contain hydrocarbons.

The nature and objects of the present invention having been completelydescribed and illustrated, what I wish to claim as new and useful and tosecure by Letters Patent is: e

1. A method for conditioning a hot wire gas detector .for use in welllogging operations in which said hot wire becomes fouled withcombustible deposits, which com- As this adjustment rotates past prisescontacting said hot wire with vapors of a volatile oxygenated organiccompound selected from the group consisting of the aliphatic afcohols,ketones, and ethers having a carbon chain of no more than 3 atoms, andigniting said vapors whereby said deposits are removed from said hotwire.

2. A method for conditioning a hot wire gas detector for use in welllogging operations in which said hot wire becomes fouled withcombustible deposits, which comprises contacting said hot wire withvapors of a volatile oxygenated organic compound selected from the groupconsisting of the aliphatic alcohols, ketones, and others having acarbon chain of no more than 3 carbon atoms, igniting said vaporswhereby said deposits are removed from said hot wire, and removingproducts formed by igniting said vapors.

3. A method for conditioning a hot Wire gas detector for use in loggingof well samples in which said hot wire becomes fouled with combustibledeposits which comprises forming a combustible mixture of air and vaporsof a volatile oxygenated organic compound selected from the groupconsisting of the aliphatic alcohols, ketones, and others having acarbon chain of no more than 3 carbon atoms, contacting said hot wirewith said mixture, igniting said mixture to burn off said deposits, andremoving products formed by igniting said mixture and burning off saiddeposits.

References (Iited in the file of this patent UNITED STATES PATENTS1,224,321 Philip May 1, 1917 1,643,155 Eisenschitz Sept. 20, 19272,595,411 Ripoche May 6, 1952 2,655,455 Steele Oct. 13, 1953

1. A METHOD OF CONDITIONING A HOT WIRE GAS DETECTOR FOR USE IN WELLLOGGING OPERATION IN WHICH SAID HOT WIRE BECOMES FOULED WITH COMBUSTIBLEDEPOSITS, WHICH COMPRISES CONTACTING SAID HOT WIRE WITH VAPORS OF AVOLATILE OXYGENATED ORGANIC CONPOUND SELECTED FROM THE GROUP